On the bottom, inside the right and left side of the headband, a plastic tag with R and L can be seen on the corresponding sides of the headband. I purchased a size 10 for me 3. The glass tube enhances the audio and spreads it in all directions evenly so it does sound better than if you just had a regular speaker pointing upwards. It?s not worth buying a cheap one when you are plugging in expensive equipment, you really need something that can protect them. However, when it comes to the Apple Watch, the charger is incredibly anemic/slow, barely getting the job done over several hours and that is assuming you can get your watch to sit flush on it in the first place. I might even go down to 50! Save yourself the trouble, spend a few more dollars on a better product. Way too small per crocs own sizing. Perfect fit thank you guys. However, the build quality, appearance and fit and finish and surpassed my expectations at the $39 price point.